I think the ability to renew ones hope/enthusiasm is really the underlying issue here, you're right on there. Some people(self incl) after some period of time can let it go and hope to the future. I'm not saying you cant have the negative feelings about how you're beloved team is being managed(woulda liked TE in 3rd) or how they've been managed in recent years(playoffs?).
Without a QB for the last 12 years(trent=fingers crossed) the playoffs have not really been a reasonable expectation(1999 #1 def)
So i just wanted to say if your like me and come back every year thinking this is the year then you should really be thankful that you have the ability to do so(even if misguided) And to those who have a tougher time seeing through the rose coloured glass, this could be the year!!